Cyclic thioether silver halide development accelerators



United States Patent ABSTRACT OF THE DISCLOSURE Process of developing a silver halide latent image in the presence of a compound of the general formula:

According to a first feature of the present invention there is provided a process for the production of a developed photographic material which comprises subjecting a material containing a developable silver salt to development by means of a photographic developing agent in the presence of a compound of the general Formula I:

where n is 0 or 1, A being methylene and B being sulphur "ice when n is 0, and A being oxygen or sulphur and B being methine when n is 1 and X and Y are the same or different and are each selected from hydrogen, alkyl, substituted alkyl, alkoxy, substituted alkoxy, aryl, substituted aryl, aryloxy, substituted aryloxy, or hydroxyl.

Alkyl groups when present preferably have up to six carbon atoms, i.e. methyl, ethyl, propyl, butyl, amyl, hexyl and their isomeric forms. Substituted alkyl groups may be any of the foregoing carrying, for example, halogen, hydroxyl, amino, cyano, carboxy, carbonamide, N- substituted carbonamide or sulphamoyl groups. Alkoxy groups When present may be similarly substituted. Aryl groups when present are preferably phenyl or homologues of phenyl and substituted aryl groups are preferably such groups carrying, for example, any of the substituent groups just referred to. Aryloxy groups when present may be similarly substituted.

Preferred compounds of general Formula I for use in the present invention are those in which A is a sulphur atom, B represents methine, X is hydrogen and Y is a substituted methyl group, the substituents being any of those referred to above.

Compounds of the foregoing formula are either known per se or are prepared by simple modification of known methods. The following Table I lists compounds suitable for use in the present invention, identifying them by reference to the foregoing Formula -I and indicates in each a literature reference or asuitable method of preparation. Where the required end product is an amide it is convenient to prepare the corresponding acid and then to convert this to the acid chloride or lower alkyl ester and react it with ammonia or an amine. Where the required end product is a hydrazide the corresponding acid is prepared which is then converted to the lower alkyl ester and reacted with hydrazine hydrate at room temperature.

TABLE I.COMPOUNDS SUITABLE FOR USE IN THE INVENTION S CH: ?Hz )n )n Analysis Compound A B Y X 11 Preparation B.P. (in C./ .P.

mm.) (in C.)

C H N S S 0 Commercially available CH 1 do OH OH OH 1 Cgg)i1ill,J.A.C.S., 1937 59, CH OEt OEt 1 ctgfih lll, .T.A.C.S., 1937 59,

1. 5 O CH CH CH 1 M. Hunt & C. S. Marrel,

J.A.C.S., 1935 57, 1691. 6 S OH H CHQCI 1 R. C. Fusondz A. J. Speziale, J.A.C.S., 1949 71, 1582. 7 S OH H CEgOH 1 R. C. Fusondz A. J. Speziale, .T.A.C.S., 1949 71, 1592. 8 S OH H CHZNHZ 1 Amination of (6) with aq. 120/112 F 40.9 7.8 8.5 43,2 ilcozhozlic NHaat of. R 40.2 7.4 9.5 42.9

o e 9 S OH H CHQCN 1 Reaction of (6) with aq. 97/0.2 55-57 F 45.4 6.1 8.4 39 9 alcoholic NaCN under R 45.4 5.7 8.8 40.1 reflux of. Note 1. 10 S OH H CHzCONHg 1 From the corresponding acid- 124-126 TIE 42.0 5.8 36.6 40.7 6.2 36.2 11 S OH H -CH2CONHCH3 1 From the corresponding acid r. 141 F 43.6 6.6 7.4 33.9 as describedin the text. R 44.0 6.8 7.3 33.5 12 S CH N CH2CONHNH2 1 do 118 F 37.4 6.3 14.6 33.4 R 37.5 6.3 14.6 33.3

NOTE 1.'0rganic syntheses, Collected Volume 2, p. 292 (1943).

NOTE 2.Whitmor e and Langlois, J.A.C.S., 1932, 54, 3441; Westphal and .Terchel, Ber., 1940, 73, 1002; V. Braun and Klor, Ben, 1940, 73, 1417.

It has been found that the presence of a compound of the said formula has a striking effect on photographic development in that when such a compound is present the time taken for development to a given density is much reduced. Specifically, when a photographic gelatino silver halide material, given a standard exposure, is developed to achieve a particular silver density in the exposed area then the development time taken to achieve that density is substantially reduced by the presence of the said compound.

Since one way of providing that a compound of Formula I is present during development of the photographic material is to provide that the said compound is included in the photographic material itself, the invention further includes novel photographic materials which comprise in a layer of the photographic material a compound of the general Formula I.

When the compound is included in the photographic material itself, it may be present in a light sensitive layer, e.g., a gelatino silver halide emulsion layer, or in any other layer of the photographic material, e.g., a sub-coat, supercoat or filter or anti-halation layer. The photo graphic material may be of a type adapted to be developed to yield colour images by reason of the presence of colour couplers in the photo-graphic material itself or in a photographic developer used therewith.

The compound of the foregoing formula may alternatively be caused to be present during the development step by including it in the developer composition which is used or by treating'the photographic material with a bath containing the compound before the development step.

The invention is of value in the production of photographic records in black and white and also in the production of photographic colour records. Its optimum point of use in the colour processing sequehce will depend on the specific sequence employed. Thus where the photographic material is intended to be processed by a reversal procedure, i.e., the image-wise exposed material is first developed to give a silver image, the residual silver salt is rendered developable and the material is then developed in a second developer which image-wise develops a dye in the material (utilising colour couplers present in the photographic material or in the second developer) the compound of general formula I is preferably included in the first or so-called reversal developer.

In processes where the photographic material is designed to be directly developed to yield a colour image (utilising colour couplers present in the photographic material or in the colour developer) the compound of the foregoing Formula I is preferably included in the colour developer.

The term colour developers is used herein to mean an aromatic primary amino colour developing agent. Such compounds are normally N,N-disubstituted p-phenylene diamines or homologues thereof, the N-substituents being alkyl, or hydroxyalkyl groups.

The quantities of compound of general Formula I required to produce the optimum effect required vary from compound to compound. The optimum quantity for use in a developer solution either for colour or black and white materials lies normally within the range 0.0001 g. mol./ liter to 0.5 g. mol./litre. When used as emulsion additives, the optimum quantities usually lie within the range 0.0001 'g. mol. to 0.5 g. mol./g. mol. of silver halide.

The presence of a compound of general Formula I is found to have no deleterious effect on the coloured images obtained by either of the foregoing processes. Whilst the effect of the compounds is essentially to accelerate the development, it is possible by variations in conditions to utilise the effect of the compounds to establish desired variance in developed contrast or eifective speed of the photographic sensitive layers. Moreover, advantage may be taken of the accelerative effect t9 reduce the quantity of silver present in the photographic emulsion, the same end result being achieved by the more etfective utilisation of the reduced silver content, and this is, of course, an important economic advantage.

Further, the use of compounds of general Formula I makes possible the use of developers of inherently lower activity, thus making available a wider choice of develop ing substances of lower cost, higher solubility, lower toxicity or affording lower amounts of stain.

The following examples will serve to illustrate the invention:

EXAMPLE I A colour photographic material constructed essentially as follows was employed:

(a) Blue-sensitive gelatino silver halide emulsion containing a colour coupler ada ted to couple to yield a yellow dye.

(b) Green-sensitized gelatino silver halide emulsion containing colour coupler adapted to couple to yield a magenta dye.

(c) Red-sensitized gelatino silver halide emulsion containing a colour coupler adapted to couple to yield a cyan dye.

(d) Paper support layer.

A photographic colour print paper having a construc tion essentially as set out above, the layer (b) and (0) being gelatine silver chlorobromide emulsions, and with the emulsion layers and colour couplers designed to afford a good colour print material (such products being commercially available) was exposed to a colour negative transparency and developed in the following developers.

DEVELOPER 1 Sodium carbonate 70.0

Potassium bromide 1.0 Hydroxylamine hydrochloride 2.0 N-ethyl-N-(Z-hydroxyethyl)-p-phenylene diamine 4.5 Water to 1 litre.

DEVELOPER 3 G. Disodium salt of ethylene diamine tetraacetic acid 1.0 Sodium sulphite anhydrous -5 2.0

Sodium carbonate 70.0

Potassium bromide 1.0 Hydroxylamine hydrochloride 2.0 N-ethyl-N-(2-hydroxyethyl)-p-phenylene diamine 4.5

Water to 1 litre.

To these developers were added various quantities o compounds of general Formula I, as identified by the numbers assigned to them in the foregoing Table I.

The sensitometric results obtained are set out in Table II the times given being the times required to reach standard characteristics for a given exposure level. It will be noted that the fog levels are not materially increased by the presence of the compound of Formula I.

Relative Log Time of Speed at Density Compound Quantity, Development, Fog 0.8 on the Char- Developer g. mol./l. ruins. acteristic Curve Used B G R R G B EXAMPLE II of 0.067 g. mol. per mol. of silver halide. To the emulsion then added a suitable quantity of a solubilised long A film of the general construct1on 1nd1catmg 1n Ex- 1S ample I (but using a film support, having a yellow filter 1 q ntagenticolour former such as one of thos? layer between layers (a) and (b) and designed as a scribed 1n Br1t1sh Patent No. 830,797. The emuls1on 18 camera material of speed ASA 64) was processed by then coated on support and the PhOtOgFaPhw the reversal method as follows. element thus obtained is exposed and processed in the The exposed film was first developed in the following usual Way for PFIPer P a substanllve Develo er A former. By comparison w1th a control emulslon coatlng p DEVELOPER A not containing the development accelerator it is found that for the same exposure level the additive reduces the l phenyl 3 pyrazolidone required processing time to two thirds of standard. Sodium sulphite (anhydrous) 50 We clalm as our mventlon: Hydroquinone 1. In a process for the production of a developed Sodium metaborate 20 p otographic material by subjecting a material containmg Potassium bromide 21) a developable silver halide latent image to development Potassium gg fjj 1.5 y m ans of a photographic developing agent, the im- Benztriazole I: I provement comprising developing said silver salt by means Water to of a said photographic developing agent in the presence of at least one compound of the formula: The film was then put 1n a hardener bath for 2 mmutes, washed for 5 minutes and re-exposed for 10 seconds with s photofiood light. It was then colour developed in the fol- 40 1320/ lowing developer for 10 minutes at 20 C. (X) 1 DEVELOPER B G. A f hexametaphosphate wherein n is 0 or 1, when n' is 0, A is methylene nd Tnsodmm PPOSPhatC 80 B is sulphur and when n is 1, a is selected fro the fiyqroxylamlqe sulphate group consisting of Oxygen and sulphur and B i sodlum sulphlte (anhydmus) methine, and X and Y are each independently se- Potassmm bromlde lected from the group consisting of hydrogen, alkyl, NethylN'hydroxyet enylene amme substituted alkyl, alkoxy, substituted alkoxy, aryl, sulphate substituted aryl, aryloxy, substituted aryloxy, and Water to make 1 litre. hydroxyl radicals The film was then put in a stop hardener bath for 3 P aqcording to Claim wherein d 60 minutes, washed for 3 minutes, bleached for 3 minutes, pound 15 present 111 photogrifphlc Qp washed for 3 minutes, fixed for 4 minutes, and finally A Pf0ceSS aficoldlngto clalm 1 Wherem aid mwashed for 3 i i the normal manna; pound 1s present in a gelatino silver hallde emulsron layer Various quantities of compounds of general Formula I were added to Developer A and the effects obtained are shown in the following Table II. The times noted are those required to reach a close match with the characeristics obtained by the control processing, for a given exposure level.

Fog

Compound g. mol./l. Development B G R 0 16 16 16 l2 0. 02 8 17 l4 08 0. 015 8 18 ll 08 0. 01 8 16 15 11 EXAMPLE In Use of the compounds as emulsion additives To a standard non-optically sensitised silver halide emulsion, a quantiy of compound 10 (Table I) is added. The quantity of compound is best taken in the proportion of the photographic material.

4. A photographic developer solution containing a silver halide developer and 0.0001 to 0.5 g. mol./liter of developer solution of at least one compound of the formula:

wherein n is 0 or 1, when n is 0, A is methylene and B is sulphur and when n is 1, A is selected from the group consisting of oxygen and sulphur and B is methine, and X and Y are each independently selected from the group consisting of hydrogen, alkyl, substituted alkyl, alkoxy, substituted alkoxy, aryl, substituted aryl, aryloxy, substituted aryloxy, and hydroxyl radicals.

5. A gelatino silver halide emulsion containing 0.0001

3,419,393 7 8 to 0.5 g. m01./g.mol. of silver halide of a compound References Cited the fmmula: UNITED STATES PATENTS 2,477,323 7/1949 Wood 96-66.3

S 3,053,656 9/1962 COlley 9666.3 3,062,646 11/1962 Dann eta] 9666.3

OTHER REFERENCES Dalziel, J. A. W. et al., Addition Compounds of 1,

wherein n is O or 1, when n is 0, A is methylene and Tl'ithiafle with Mercury and Silver B is Sulphur and when n is 1, A is Selected f 10 J. Chem. Soc., 0. Inorg. Phys. The0ret., 1966 (3), 233-5.

the group consisting of oxygen and sulphur and B i t z f 31d X and Y ar et each firildtl nd llk l- NORMAN G. TORCHIN, Primary Examiner.

ec e rom e group consis mg 0 y rogen, a y

substituted alkyl, alkoxy, substituted alkoxy, aryl, 1F DAVISAsslSmm Examiner substituted aryl, aryloxy, substituted aryloxy, and 0 US. C1.X.R.

hydroxyl radicals. 96-95; 107 

